Evaluation of Shock-Absorption Performance of Magnetorheological Fluid Under High-Speed Impact

Abstract

Magnetorheological (MR) fluids are smart fluids which have a property that the viscosity rapidly increases by applying a magnetic field, and they have already been put to practical use in automobile dampers and seismic isolation devices. To expand the practical application of the MR fluid, various evaluations of shock-absorption performance under high-loading conditions are needed. Therefore, we decided to investigate its performance in high-speed impact conditions. Impact experiments were conducted in different liquids—tap water, two types of silicone oils with different kinematic viscosities, and an MR fluid—and it was investigated how the properties of each liquid affect the shock-absorption performance. Accordingly, it was found that kinematic viscosity and compressibility affect shock-absorption performance. The kinematic viscosity did not affect the speed attenuation of the projectile. Furthermore, it was found that the compressibility affected the pressure wave generated by the entry of a projectile into the liquid.